Space Station Remains a Work in Progress, One Great Big Piece at a Time
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I'm Barbara Klein. And I'm Steve Ember with EXPLORATIONS in VOA Special English.
This week we tell about the most recent flight of the space shuttle Atlantis. We also tell about a new spacecraft that will explore the polar areas of Mars. And we tell about an upgrade to the Hubble Space Telescope.
The space shuttle Atlantis returned safely to earth on June twenty-second after fourteen days in space. Atlantis landed at Edwards Air Force Base in southern California. Rainy weather at Kennedy Space Center in Florida prevented the shuttle from landing there. Rain could have damaged the heat protections system on the spacecraft. This was the first shuttle launch of the year for the United States space agency. The shuttle traveled more than nine million kilometers.
The main goal was to continue construction of the International Space Station. This flight of the shuttle brought a new piece of equipment to the space station. The piece, called a truss, weighs seventeen and one-half tons.
It includes large solar energy collectors more than seventy-three meters long called solar arrays. The solar arrays change the light of the sun into electricity providing power to the space station. Each solar array contains many thousands of photovoltaic cells. The extra power will be needed in the future when other missions add new pieces to the space station.
The truss also contains a Solar Alpha Rotary Joint. This device keeps the solar arrays pointed toward the sun at all times. This permits the arrays to continuously gather electricity for the space station.
During the mission, American astronaut Sunita Williams set a major spaceflight record. She has spent more time in space than any other woman. She worked on the international space station for more than six months. Ms. Williams also set a record for spacewalking by a female astronaut. She has spent more than twenty-nine hours working outside the space station.
Ms. Williams was launched into space on the shuttle Discovery on December ninth, two thousand six.
In addition to her other records, Sunita Williams became the first person to run a marathon in space. She ran in place on an exercise machine called a treadmill on April sixteenth. That was the same day as the Boston Marathon in Massachusetts. In fact, she was officially entered in the race. Ms. Williams finished the forty-two kilometer race in four hours and twenty-four minutes.
Last month, astronaut Clayton Anderson replaced Ms. Williams on the space station. He joined Russian cosmonauts Fyodor Yurchikhin and Oleg Kotov.
The shuttle flight had several major problems. In fact, one crisis temporarily threatened the one hundred billion dollar space station. Part of the station's computer system failed when astronauts connected the new truss to the space station.
Three navigation computers in the Russian section failed and could not be restarted. These computers control the position of the station in its orbit around the Earth. Control of the space station was then passed to the space shuttle. The shuttle had enough fuel to hold the space station's position for several days.
Another computer problem affected the environmental system of the space station. That system provides oxygen for the station and removes the carbon dioxide gas from the air. The Russian cosmonauts were able to repair the computers, but only after several tense days.
The Atlantis flight was supposed to last eleven days, but the problems extended it to fourteen days. One main problem took place during the launch. Part of the shuttle's heat protection system came loose. NASA said the damage was not so severe that it threatened the shuttle. However, it required an extra spacewalk by a shuttle astronaut to repair. Astronauts used the fifteen-meter-long robotic arm of the shuttle to inspect the heat shield after the shuttle left the space station.
Still, the astronauts and NASA were satisfied with the mission. Commander Rick Sturckow said the astronauts were able to solve all the problems and complete the mission.
NASA had expected to launch Atlantis in March. But a hail storm damaged the fuel tank. This mission was the twenty-eighth for Atlantis. It was the one hundred eighteenth flight in the space shuttle program.
The next space shuttle flight is planned for August ninth. The shuttle Endeavor will add another truss to the International Space Station.
NASA continues to explore the red planet, Mars. A new spacecraft, the Phoenix Mars Lander, will investigate the planet's north polar area next year. The spacecraft will land in a place that is believed to have huge amounts of frozen water and, possibly, conditions for life.
Scientists have found that Martian polar areas hold a surprising amount of water. In March, the European Space Agency announced findings from its Mars Express spacecraft. It said measurements showed that there was enough water trapped in the southern polar area of Mars to cover the entire planet to a depth of eleven meters.
A special device on Mars Express took the measurements. The instrument is called the Mars Advanced Radar for Subsurface and Ionospheric Sounding, or MARSIS. NASA and the Italian space agency jointly built MARSIS.
The device uses radar to "see" through levels of ice to the ground surface beneath. MARSIS found that icy material at the southern polar area was three point seven kilometers deep in some places.
Now NASA will explore the north polar area with the Phoenix Mars Lander. It is expected to be launched in August and to reach Mars in May or June of next year. It will dig into icy layers of material using its robotic arm.
One important instrument on the lander is the Thermal and Evolved-Gas Analyzer. It will help scientists study water and substances in the Martian soil including the elements hydrogen and carbon. These are considered the building blocks of life. The instrument will heat materials found on the surface to examine their chemical composition. Another device will test soil by adding water to it and examining the results.
The Phoenix Mars Lander will also have a special set of cameras that will be able to see in different wavelengths of light. NASA scientists hope that the lander will give them a better understanding of the history of water on Mars. They consider this important if they are to find out if life could or did exist there.
The telescope is the most important tool in astronomy. Scientists have been learning more and more about space ever since Galileo first used the telescope to observe the stars in the seventeenth century. In nineteen ninety, NASA sent the Hubble Space Telescope into orbit around the Earth.
Over the years it has been the most important telescope in modern astronomy. Using Hubble, scientists have been able to learn the age of the universe, take pictures of far-away young galaxies and study the mysteries of the universe. Now, NASA is planning a new mission to update the telescope next year. This project, called Servicing Mission Four, will add important instruments.
Scientists designed Hubble to be visited by NASA astronauts who could fix and update the telescope. Over the years, NASA has sent several teams to carry out these updates. Each of these missions has made Hubble even more powerful. Servicing Mission Four will fix old parts and add new, advanced instruments that can make new observations.
Hubble's gyroscopes are some of the old parts that will be fixed. The gyroscopes help control the telescope. Also, new batteries will be added to keep the telescope operating. Thermal blankets will also be added, which will help keep the instruments warm.
The instruments that will be added are called the Cosmic Origins Spectrograph, or COS, and the Wide Field Camera Three. The COS will be able to observe and measure the structure of the universe, and how the universe has changed over time. The Wide Field Camera Three will let Hubble see deeper into the universe. It will also permit the telescope to observe more kinds of light that come from different places in the universe.
These improvements are expected to keep the Hubble telescope working until at least two thousand thirteen.
This program was written by Erin Braswell and Mario Ritter who was also the producer. I'm Steve Ember. And I'm Barbara Klein. You can read and listen to this program on our Web site, voaspecialenglish.com. Join us again next week for EXPLORATIONS in VOA Special English.